纳滤（NF）过程中的分离可能由于各种现象而发生。在所有的膜工艺中，当感兴趣的组分比膜的孔径大得多时，就会进行筛分。当小的、不带电的分子能够以体流通过膜时，就会发生对流。扩散发生在跨膜的浓度梯度下，但渗透物种在膜基质中的溶解度也会影响迁移。在发生对流和/或扩散的NF系统中，回收将对溶质的截留产生直接影响。随着回收率的增加，膜进料侧本体溶液中的溶质浓度增加，导致对流和扩散传输增加。由于聚合物基质的物理变化、有机和无机滤饼层的形成以及浓度极化效应，膜的传质阻力会发生变化。 这些传质阻力会降低水和溶质的通量。本文研究了传质阻力和回收率对纳滤分离的影响。研究了天然水和特定的有机溶质。

Separation in nanofiltration (NF) processes can occur due to a variety of phenomena. In all membrane processes, sieving occurs when the constituent of interest is much larger than the pore size of the membrane. Convection occurs when small, uncharged molecules are able to pass through the membrane with the bulk flow. Diffusion occurs under a concentration gradient across the membrane, but solubility of the permeating species in the membrane matrix will also impact transport. In NF systems where convection and/or diffusion occur, recovery will have a direct impact on the rejection of solutes. As the recovery is increased, the concentration of solutes in bulk solution on the feed side of the membrane increases, resulting in an increase in convective and diffusive transport. The mass transfer resistance of a membrane can change due to physical alterations of the polymeric matrix, the formation of organic and inorganic cake layers and concentration polarization effects. These mass transfer resistances can decrease the flux of water and solutes. This paper investigates the impact of mass transfer resistance and recovery on nanofiltration separation. Both natural waters and specific organic solutes were investigated.